Method of water purification

ABSTRACT

Method of purifying water, such as sea water, by low temperature evaporation thereof under conditions of reduced pressure to produce a gaseous mixture of water vapor and non-condensible gas and, subsequent to substantial condensation of the water vapor, encapsulation of the remaining uncondensed water vapor and the non-condensible gases in a downwardly flowing vertical column of foamed encapsulating liquid.

United States Patent Brown [451 *July 4, 1972 METHOD OF WATERPURIFICATION R r n Ci [72] Inventor: Melvin Henry Brown, Leechburg, Pa.UNITED STATES PATENTS,

[73] Assignee: Aluminum Company of America, Pitt- 2,384,860 9/1945Thomas ..62/475 X sburgh, Pa. 2,759,882 8/1956 Notice: The portion ofthe term of this patent sub- 3394055 7/1968 3,498,886 3/1970 sequent toSept. 15, 1987, has been disclaimed 3,528,890 9/1970 3,396,086 8/1968Starmer ..203/26 [221 Filed; Aug.14,1969

Prima Examiner-Norman Yudkoff 2| A N .1 850,160 1 I PP 9 AssistantExaminerl-Iiram H. Bernstein Related U.S. Application DataAtt0rney-R0bert E. lsner and Carl R. Lippert [63] Continuation-impart ofSer. No. 571,514, Aug. 10, [57] ABSTRACT 1966- Method of purifyingwater, such as sea water, by low temperature evaporation thereof underconditions of reduced pressure [52] U.S.Cl ..203/l1, 203/100, 202/205,to produce a gaseous mixture of water vapor and [5 Int Cl 0 densible gasand, subsequent to substantial condensation of [58} Field of Search..203/10, 1 1,4, 100, 26; the vapm encapsulam the emammg uncndensedwater vapor and the non-condensible gases in a downwardly flowingvertical column of foamed encapsulating liquid.

5 Claims, 11 Drawing Figures SHEET 1 0F 5 P'A'TENTEDJUL 4 I972 INVENTOR.

MEL VIN H. BRO WN ATTORNEY PATENTEDJUL 4 I972 SHEET 2 OF 5 INVENTOR.MELVIN H. BROWN BY m A T TORNE Y PATENTEU JUL 4 I972 3,674,652

sum 30F s INVENTOR.

MELVIN H. BROWN xix 14% ATTORNEY PATENTEDJUL 4 I972 SHEEI '4 0F 5INVENTOR. MELV-IN: H. BROWN ATTORNEY PMENTEDJuI. 4 I972 SHEET 5 OF 5 INVENTOR. //Z V/A A6 1920 MV METHOD OF WATER PURIFICATION This applicationis a continuation-in-part of my earlier ap plication Ser. No. 571,514filed Aug. 10, 1966.

This invention relates to purification methods by which a saline water,which also contains a non-condensible gaseous component, is treated tolower its chemical content to a level tolerable to the intended purposewhich may be industrial in nature, the provision of water forirrigation, the provision of water for consumption by humans or animals,or other purpose. Sea water and brackish water are outstanding examplesof saline waters which contain chemicals, contain non-condensible gas,and which usually require some purification. The general object of thisinvention is to purify such waters while overcoming difficultiesinherent from the presence in the water of such non-condensible gaseouscomponents as absorbed air, products of organic or inorganic reactions,or the like. Various approaches to the purification of such waters areknown, including those which initially vaporize the water to effect theseparation of water from chemical. The present invention offersadvantages economically over many other processes particularly wherepurification of large volumes of water is effected through vaporization.

In the practice of the methods of this invention the saline waterpresented for treatment is evaporated at less then atmospheric pressurethereby producing, continuously over any given time period, a gaseousmixture containing water vapor as an essential component andnon-condensible gas as an unavoidable component. As this gas mixture isproduced it is subjected to a condensing step during which a recovery ofa substantial portion of the water vapor content of the gaseous mixtureis effected to obtain at least part of the purified product desired. Aswill appear, this condensing step may be the only step in which recoveryof purified water is achieved; but usually I also prefer to effectfurther condensation during the gas removal step which follows thecondensation step. In general, I prefer to condense prior toencapsulation of the gaseous mixture about 60 to about 95 percent oreven greater by weight of the water vapor content of the gaseous mixtureformed by the evaporation, since this will usually ensure optimumover-all economies in the operation of the method of the invention.

After this condensation is effected the remainder of the gas mixture isencapsulated, continuously over the period of its availability, in aliquid and at least in part by defining liquid film in the upperextremities of elongate, substantially vertical chambers to formencapsulated gas bodies some of which at the time of encapsulation maybe substantially equal in horizontal cross sectional area and dimensionto the horizontal cross section of the chamber in which the body isformed and in such manner that at least a multiplicity of said bodiesare disposed in abutting interfacial engagement with the walls of eachsuch chamber. After such formation in the upper extremity of a verticalchamber each body thus encapsulated is moved downwardly and compressedin the chamber by the formation above it of further such encapsulatedbodies. As the result of this continuous encapsulation in liquid ofbodies of the gas mixture and the compression and downward movement ofthe encapsulated bodies in the vertical chambers and their eventualrelease from the lower extremities thereof, the necessary maintenance ofpressure in the system at the desired sub-atmospheric level is achieved.

The encapsulating liquid may vary in nature subject to the usuallimitations as to toxicity, odor, and the like attendant upon the use towhich any condensible portion of the gas mixture may be put and subject,further, to such viscosity requirements as will promote flow in thevertical chambers at the desired rate, all as hereinafter discussed.

The term encapsulated and its variants as used herein are used to conveythe fact that bodies of the gas mixture are at least partially definedand surrounded by a liquid phase, at least a portion of which is in theform of a film. To avoid implications arising from specialized use ofsuch terms in botanical, physiological and other arts, the terms areherein defined as used in the derivative sense of little chest or box.As will appear, the wall or media which defines the capsule of gasmixture is necessarily essentially liquid to provide flexibility undercompression in the vertical chamber, but initially, at least, a portionof the capsule wall may be defined by the wall of the vertical chamber.

The invention is procedural in character and does not contemplate anyparticular apparatus within its scope. For purposes of illustration anddescription of the invention reference will be had to the accompanyingdrawings which schematically indicate general arrangements of parts andmechanisms grouped to apply the methods of the invention in variousways. In these drawings like numerals designate like parts.

This application is a continuation-in-part of my earlier applicationSer. No. 571,514 filed Aug. 10, 1966.

FIG. 1 illustrates partly in elevation and partly in section one plan ofoperation of the invention wherein two separate condensing operationstake place and in which the condensate is used as encapsulating liquid;

FIG. 2 illustrates partly in elevation and partly in section a plan ofoperation somewhat similar to that shown in FIG. 1 except that theproduct of the second condensation is sent to waste and an impure water,used as the coolant in the first condensation, is used as encapsulatingliquid;

FIG. 3 illustrates a modification of FIG. 1 wherein the elongatechambers 38 are shortened and deliver into a confined vertical commonstream;

FIG. 4 illustrates, largely in section, another plan of operation of theinvention;

FIG. 5 illustrates, partly in section and partly in elevation,modification of the plan of operation illustrated in figures of lowernumber to the use of immiscible encapsulating liquid;

FIG. 6 illustrates the operation of encapsulating, compressing, andcondensation steps used in the practice of the methods of waterpurification which embody the present inventions;

FIG. 7 illustrates, largely in section, another method of practicing theinvention in which encapsulation of the gas mixture is by foaming thegas and compressing the foamed gas while condensing its condensibleportion, the plan of operation shown being, otherwise, that shown inFIG. 5; and

FIG. 8 is a view, largely in section, of a modification of theoperational plan illustrated in FIG. 1, the encapsulating of the gasmixture being accomplished by foaming;

FIG. 9 is an enlarged view of a portion of FIG. 8;

FIG. 10 is an enlarged fragmentary plan view of an encapsulation chamberconstruction;

FIG. 11 is a fragmentary elevational view of the structure illustratedin FIG. 10.

Referring to FIG. 1, the system shown involves evaporator 26, a firstcondenser 31, and a plurality of vertical chambers or column formers 38.The water to be purified is lifted from a source 20 by pump 22 throughpipe 23 to tank 24 from whence it is lifted through leg 25 to theevaporator 26 where a portion is evaporated to form a gas mixture ofwater vapor and non-condensible gas which passes through passage 30 tocondenser 31. The action inthe vertical chambers 38 helps to furnish thevacuum which lifts the water through leg 25, lowers the pressure in theevaporator and induces the flow of the gas mixture formed onevaporation. Unevaporated water 27 collects in the bottom of evaporator26 and from thence flows to waste through leg 28, basin 29 and itsoverflow pipe 21. Such heat as may be added to the water canconveniently be added at basin 24. Cool water flowing from source 33through coil pipe 32 to outlet tank 34 causes condensing of part of thewater vapor to obtain purified water which collects in the bottom of thecondenser and passes therefrom through leg 35 into distillate basin 42from whence it flows through an overflow 21 to the ultimate collectionpoint. The uncondensed portion of the gas mixture flows through passage36 to the distributing head 37 of a collection of a plurality ofvertical chambers 38 which may be formed of tubes of any cross-sectionalshape, but preferably round. The encapsulating liquid, in this case thedistillate contained in distillate basin 42, is

brought to the distributing head 37 through tube 44 and its heatexchanger 45 under the action of pump 43. In distributor head 37 thedistillate flows from pipe 44 onto a perforate distribution plate 70, anexample of which is shown in FIG. 6, and thence down upon the sheet 71through which open the upper extremities of the vertical chambers 38.The gas mixture flowing into distribution head 37 and arounddistribution plate 70 enters the openings into the upper extremity ofvertical chambers 38 and is there encapsulated, by the liquid flowing insaid head, into somewhat elongate gas slugs the horizontal crosssectionof which correspond in area and dimension to the horizontalcross-section of the chamber in which they are formed as, for example,in the general manner shown in US. Pat. No. 885,301 of 1908. After eachgas body or slug is encapsulated it is forced downwardly by the weightof the succeeding encapsulated body in that chamber and is also by thatweight compressed. Since displacement of the encapsulated body isimparted by the weight of encapsulating liquid disposed thereabove, therate of displacement in the upper portions of the chamber will benecessarily slow. As encapsulation in a chamber progresses, theencapsulated body is further compressed while portions thereof which arecondensible may also be condensed. Also, portions of the encapsulatedbody may be dissolved in the encapsulating liquid. Eventually, eachencapsulated body of the gas mixture arrives in its downward movement atthe exit of the chamber where the remaining gas leaves the chamber andexits through distillate tank 39 to the atmosphere. The encapsulatingliquid, plus any distillate condensed from the gas mixture, flows intodistillate tank 39 and from thence through pump 40 to tank 42. In theoperation illustrated in FIG. 1 a transfer pipe 41 and pump 40 isprovided to transfer from distillate tank 39 to tank 42. The removal ofthe gas mixture from the system through the elongate chambers 38 iscontinuous and positive and maintains a less than atmospheric pressurein the system at equilibrium conditions which are the function of therate of evaporation, density and temperature of the encapsulatingliquid, and the length and number of the vertical chambers 38. The planof operation illustrated in FIG. 1 contemplates a recovery in twocondensation steps, one at condenser 31 and one in vertical chambers 38.For the latter purpose the temperature of the encapsulating liquid andof the chambers 38 is maintained at a temperature below the condensingpoint of the condensible water vapor in the encapsulating gas mixture.In the specific system illustrated, proper temperature control can beaccomplished by use of any liquid cooling means located at 45.

Where comparative purity factors will tolerate it, the system shown inFIG. 1 can be modified to the plan of operation shown in FIG. 2 whereinthe coil pipe 32, used to bring coolant to the condenser 31, can berearranged to feed encapsulating liquid to the header 37. The liquidflowing from the lower end of the vertical chambers 38 is received in abasin 52, maintained at chamber sealing level by overflow pipe 21, andthe overflow sent to waste. Purified water is, therefore, only recoveredat condenser 31 and flows through leg 50 to distillate basin 51 andthrough overflow pipe 21 to a proper collection point.

In the plans of operation illustrated in FIGS. 1 and 2, a verticalchamber 38 having a circular cross-section of one-fourth inch diameterwould for best results have a length of about 45 feet if water, whetherpure or impure, is used as the encapsulating liquid. While there isnothing impractical in such a situation, a more preferred manner ofhandling the length of vertical chamber desired is illustrated in themodification of FIG. 3. In FIG. 3 the plan of operation shown is that ofFIG. 1 previously described with the exception that the verticalchambers 38 are shortened to terminate in a single vertical chamber 54.Thus the effective height of the vertical chamber, considered in total,is not changed from whatever is chosen as the preferred height, but themultiplicity of chambers 38 is eliminated at a point after thecross-sectional dimensions of most of the encapsulated gas bodies hasbecome less than that of the chambers 38. The situation just generallydescribed is shown more specifically in FIG. 6. Referring to FIG. 6 inthe initial reaches of chambers 38, as illustrated at area 100, theinitially formed bodies of the gaseous misture may be somewhat elongate,as shown at 74, and may have, as previously stated, a horizontalcross-sectional area equal in area and dimension to the similarcross-section of the chamber 38. In any event, such bodies will beencapsulated, at least in part, by a defining liquid film and in suchmanner that at least a multiplicity of said bodies are disposed inabutting interfacial engagements with the walls of each such chamber. Asthe bodies 74 pass downwardly in the chambers 38 under the compressionand downward gravitational force of similar bodies encapsulated in thechambers 38 at points above, the bodies tend to become smaller andcircular in cross-section, as indicated at 74 at area 101 of saidchambers 38. Finally, as compression of these bodies continues, thebodies largely diminish in horizontal cross-sectional area so that theybecome gas bubbles surrounded by a stream of encapsulating liquid, plus,of course, any liquid which may be the result of condensation of thecondensible portions of the encapsulated gas mixture. The result becomesthat illustrated at 74 in the area 102 indicated in FIG. 6. It is atabout this point that we prefer to release the compressed bodies ofgaseous mixture from at least some of the chambers 38 to a confinedcommon stream defined by a single channel 54, thus creating thesituation shown at areas 103 and 104 of FIG. 6. This common channel 54into which the effluent of chambers 38 eventually merge represents aconfined common stream which is maintained at a flow velocity sufiicientto cause movement of the condensed encapsulated bodies 74 away fromtheir point of delivery from chambers 38 to said common stream and,eventually, to the distillate reservoir 39 at which point the remainingbodies 74, now perhaps composed essentially of non-condensible gas, arereleased into the atmosphere through the seal formed by reservoir 39.Such flow velocity of the confined common stream sufi'lcient to causethe movement of the condensed encapsulated bodies away from the chambers38 is relatively high as compared to the velocity of the encapsulatingliquid in the upper portions of the chambers 38.

In the unit shown in FIG. 4 the condensing action of vertical chambers38 and the common stream 54 is augmented by providing in the headerchamber 37 the packing 60 which is rested on the perforate plate 61, toprovide additional surface area and impede rate of flow, and over whichis sprayed, as from spray head 58, recycled distillate 59 from pipe 44.The effect is to preliminarily condense a part of the water component ofthe gas mixture from evaporator 26. The product of this condensation andthe recycled distillate from spray 59 furnish the encapsulating liquidfor the vertical chambers 38.

The cross-sectional shape of the vertical chambers in whichencapsulating is initially accomplished may vary from a circle to asquare, may be a quadrant or a half ofa circle, or may be triangular orof other suitable shapes. The cross-sectional shape is not critical tothe obtainment of the results hereinabove discussed. While the preferredcross-sectional shape of the chambers is circular, oblate, orapproaching a circle, since such lend themselves to the ready formationof the encapsulated bodies of gas, economic considerations may dictatethe use of other configurations, such as, for example, those illustratedin FIGS. 10 and 11. As there shown tube-like chambers are defined by theinterfacial disposition of a corrugated sheet 122 and flat sheet 124.These interfacially engaged corrugated and flat sheets are then wound ina spiral fashion to provide alternating flat and corrugated sheet layerswherein the crests of the corrugations in each sheet 122 abut the flatsheet 124 of the adjacent layer. Such construction facilitates theprovision of a multiplicity of chambers having bell shapedcross-sections within a relatively small space and in an inexpensivemanner. A wire mesh screen 126 is desirably positioned atop the chambersand the efiective screen openings therein are advantageously sized to besmaller than the effective openings of the bell shaped chambers. Thearea of the cross-section of the vertical chambers has practical limitsreadily ascertained for any particular cross-sectional shape and anyparticular encapsulation liquid. Normally this area is relatively small,as for example and as pointed out earlier where water is used as theencapsulation liquid, a circular cross-section of A inch diameter can beused. The crosssectional area of these chambers 38 will, of course,efl'ect efficient encapsulation because, in accordance with known laws,the viscosity of a given liquid is a limitation not only to its rate offlow but, also, to it ability to bridge a cross-sectional area.Generally, we prefer to select a vertical chamber or column former 38which defines a column having a cross-sectional area which responds to aformula in which the length of the perimeter wetted by a liquid therein,expressed in inches, multiplied by the maximum distance, expressed ininches, between two points in the area produces a number less than 0.6.In our preferred practice, using water in the encapsulating liquid, weprefer dimensions which when multiplied as above produce a number ofabout 0. 12.

The length of the column formed by a vertical chamber, and its attendantcommon stream chamber if one be used, will vary with the vacuum desiredin the operation and the weight of the encapsulating liquid. Forinstance, where water is used as the encapsulating liquid, columnlengths of up to 60 feet are desirable; but if mercury is used as theencapsulating liquid the same general results may be obtained by use ofcolumn lengths of 3 to 5 feet. Where mercury or other water-immiscibleencapsulating liquids are used, the liquid is recirculated. Such a planof operation is shown in FIG. 5, which illustrates a modification of theoperations generally described with reference to FIGS. 1, 2 and 3. Inthis modification the source of the immiscible liquid 64, which isindicated in the drawings as heavier than water but may be the opposite,is the added reservoir 65 from which it is lifted to pump 43 throughtube 44 to encapsulating position. When the encapsulated gas bodies, andthe condensate of the water vapor, is delivered to basin 39 theimmiscible liquid 64 separates in basin 39 from where it is transferredby means of pump 80 to the reservoir 65 for further use. Heat exchangers45, or other cooling devices, are operated when desirable to maintaintemperature within the vertical columns to efiect the desiredcondensation of water vapor from the gas mixture.

In some instances it may be useful to encapsulate the gas bodiesentirely in a liquid film, such as in a foam as indicated by way ofexample in FIGS. 7 and 8, each showing a plan of operation such asgenerally described with reference to FIG. 1.

The plans of operation indicated in FIGS. 7 and 8 differ from planspreviously described herein only in that encapsulation of the gasmixture is by way of foaming. In FIG. 7, the encapsulating liquid is animmiscible foaming oil 64. While use of a multiplicity of elongatechambers of small cross-section is preferred, encapsulation in foampermits of the use of chambers of somewhat larger cross-section asillustrated by the single vertical column 817 As shown, thecross-sectional area of this column may be reduced in its lower reachessince the encapsulated gas mixture will become compressed at these lowerpoints. In the operation illustrated in FIG. 7 the foaming oil 64 isdelivered through pipe 44 by the action of pump 43 to oil bath 91. Thegas mixture from condenser 31 flows through pipe 36 to the perforatedend thereof 90 from which it is delivered, through perforations 92, toand through the oil bath to form foam 83 which fills column 81. Thisfoam is composed of the gas mixture surrounded by the oil film and asfurther foam is formed the first-formed foam travels downwardly and iscompressed in the column former 81. Simultaneously, the

water vapor in the foamed gas mixture may be partially condensed. Thecompressed downwardly traveling foam exits from the lower end of columnformer 81 into the receiving, and column sealing, basin 39 whereuncondensed water vapor and gaseous uncondensibles are released toatmosphere and the distillate is separated from the immiscible oil. Inthe operation illustrated in FIG. 8 water which contains a foamingagent, such as a foam-promoting detergent which produces a stable foam,is used as the encapsulating liquid and is recycled, additional foamingagent being added to the recycled water as dilution due to condensationmay require. Referring to FIG. 8, water from reservoir 39 is raised bypump 43 through pipe 44 to the top of the vertical column 81 suchcooling as may be required being furnished at heat exchanger 45. Thiswater will, of course, contain some foaming agent which is supplemented,as desired, by valving detergent from supply tank 86 through valve 87into the water. This recirculated water, containing adequate foamingagent, is released onto a bed of packing, or the like, such as theillustrated mat of screen 88 which rests on perforate plate 82 and thereit encounters the gas mixture flowing from condenser 31 and encapsulatesthe gas in foam 83, which foam enters the column former 81 where it iscompressed by the weight of the constantly added newly formed foam andeventually flows downwardly into the basin 39 where any uncondensedwater vapor and the gaseous uncondensibles are released to theatmosphere. Preferably the perforations in plate 82 are bridged by ascreen, such as a number 40 mesh wire screen, as illustrated at 94 inFIG. 9.

When water with a foaming agent additive is employed as theencapsulating liquid as noted above, the upper portion of each of theencapsulating chambers 38 will be filled with multiplicities of filmencapsulated bodies of non-condensible gas and residual water vapordisposed in abutting interfacial relation with the walls of the chambersand with each other. The number and degree of such encapsulated bodiesdisposed in the upper portions of the chambers 38 will depend upon thedimensions of the encapsulated bodies and the cross-sectional dimensionsof the chambers. For any given unit anywhere from one to a substantialnumber of liquid film bounded encapsulated bodies may be disposed at anygiven cross-section thereof.

The vertical chambers 38, as illustrated in the schematic drawingsattached hereto, are conveniently shown as straight tubes. This is not anecessary condition. The chamber, or column former 38, must, to obtaincompressive effect, have an over-all vertical component but this may beachieved in a helical, curved or serpentine column. The exact altitudeor shape of these chambers or column formers is of no consequence solong as a component generally vertical to the earth exerts a downwardcompressive thrust by reason of the gravitational force of the capsuledgas mixture and its encapsulating liquid. The effective over-all lengthof the chambers, in the preferred aspects of the invention, is soselected with respect to the temperature and the velocity of flow of theliquid therein as to cause adjacent the lower extremity of said chambersa ratio of volume of encapsulated gas to volume of encapsulating liquidof not greater than 1.5 and, usually between about 0.05 and 1.5.

The receiving basins or delivery basins or reservoirs indicated at 29,33, 34, 39, 42, 51 and 52in the accompanying drawings are also sealingmeans for the legs or pipes extending into them, therefore to maintain,in the manner the liquid in the leg of a barometer is maintained, theliquid in said legs. The height of the legs will, of course, be adjustedin accordance with known principles to this end. The extent to whichpumps are used to lift, or assist in the lift or transfer of liquidwill, as usual in the art, be dictated by need and by the cost ofpumping power at the site of the practice of the invention.

Having thus described my invention, I claim:

1. In a distillation type system for the production of discretequantities of a utilizable fresh water product from an externallyavailable source of saline water the steps of l. continuouslyevaporating a portion of a supply of saline water at less thanatmospheric pressure to produce a gaseous mixture containing water vaporand non-condensible components,

2. continuously replenishing said supply of saline water by introductionof fresh saline water from said externally available source thereof,

3. continuously removing unevaporated portions of said saline water fromsaid supply,

4. initially condensing a substantial portion of said water vapor fromsaid gaseous mixture to produce a discrete readily removable fresh watercondensate,

5. continuously removing portions of said discrete fresh watercondensate from the locus of condensation thereof to provide a discreteimmediately utilizable product,

6. continuously encapsulating, essentially within a multi-elementbubble-like foam constituted by a multiplicity of interengaged films ofencapsulating liquid, bodies of the non-condensible components and theresidual water vapor of said gaseous mixture in the upper portion of atleast one elongate substantially vertical chamber in such manner thatsuch foam encapsulated bodies during the early portion of theirsubsequent downward displacement are at least compositely substantiallyequal in area and dimension to the horizontal cross-section of saidchamber,

7. selectively imparting downward displacement and concurrentcompression of said encapsulated bodies within the upper portion of saidchamber by the weight of the liquid defining subsequently encapsulatedbodies disposed thereabove to provide an effluent deliverable from thelower portion thereof,

8. and maintaining the temperature of the encapsulating liquid below thecondensation point of the water vapor contained within said encapsulatedbodies to effect substantial condensation thereof during the downwarddisplacement of said bodies.

2. In a distillation type system for the production of discretequantities of a utilizable fresh water product from an externallyavailable source of saline water the steps of l. continuouslyevaporating a portion of a supply of saline water at less thanatmospheric pressure to produce a gaseous mixture containing water vaporand non-condensible components,

2. continuously replenishing said supply of saline water by introductionof fresh saline water from said externally available source thereof,

3. continuously removing unevaporated portions of said saline water fromsaid supply,

4. initially condensing a substantial portion of said water vapor fromsaid gaseous mixture to produce a discrete readily removable fresh watercondensate,

5. continuously removing portions of said discrete fresh watercondensate from the locus of condensation thereof to provide a discreteimmediately utilizable product,

6. continuously encapsulating, essentially within a multi-elementbubble-like foam constituted by a multiplicity of interengaged films ofencapsulating liquid bodies of noncondensible components and residualwater vapor of said gaseous mixture in the upper portions of amultiplicity of elongate substantially vertical chambers in such mannerthat said foam encapsulated bodies, during the early portion of theirsubsequent downward displacement, are at least compositely substantiallyequal in area and dimension to the horizontal cross-section of saidchambers, said chambers having a horizontal cross-sectional area of suchcharacter that the product of the length in inches of the wettedperimeter thereof and the maximum distance in inches between any twopoints thereon has a numerical value of less than 0.6,

7. selectively imparting downward displacement and concurrentcompression of said encapsulated bodies within the upper portions ofsaid chambers by the weight of the liquid defining subsequentlyencapsulated bodies disposed thereabove to provide an effluentdeliverable from the lower portions thereof, 8. releasing the effluentfrom said multiplicity of chambers into a confined common stream havinga flow velocity that is relatively high compared to the rate of flow ofliquid through said chambers and is of a magnitude to effectdisplacement of said effluent and any gas bodles contained erem awayfrom said chambers and transfer thereof to a location external of thelocus of evaporation,

9. and maintaining the temperature of the encapsulating liquid below thecondensation point of the water vapor contained within said encapsulatedbodies to effect substantial condensation thereof during the downwarddisplacement of said bodies.

3. The method according to claim 1 wherein the encapsulating liquidcomprises water and a foaming agent and including the step of at leastpartially recycling the encapsulating liquid.

4. The method according to claim 1 wherein the encapsulating liquidcomprises water and a foaming agent and including the steps of removingan amount of liquid corresponding to the condensation product in theeffluent from said chambers, replenishing the remaining encapsulatingliquid with foaming agent and returning the replenished encapsulatingliquid to the upper extremity of said chamber to effect encapsulation offurther of said bodies.

5. The method as set forth in claim 2 wherein said product has a valueof about 0.12.

2. In a distillation type system for the production of discretequantities of a utilizable fresh water product from an externallyavailable source of saline water the steps of
 2. continuouslyreplenishing said supply of saline water by introduction of fresh salinewater from said externally available source thereof,
 2. continuouslyreplenishing said supply of saline water by introduction of fresh salinewater from said externally available source thereof,
 3. continuouslyremoving unevaporated portions of said saline water from said supply, 3.The method according to claim 1 wherein the encapsulating liquidcomprises water and a foaming agent and including the step of at leastpartially recycling the encapsulating liquid.
 3. continuously removingunevaporated portions of said saline water from said supply, 4.initially condensing a substantial portion of said water vapor from saidgaseous mixture to produce a discrete readily removable fresh watercondensate,
 4. The method according to claim 1 wherein the encapsulatingliquid comprises water and a foaming agent and including the steps ofremoving an amount of liquid corresponding to the condensation productin the effluent from said chambers, replenishing the remainingencapsulating liquid with foaming agent and returning the replenishedencapsulating liquid to the upper extremity of said chamber to effectencapsulation of further of said bodies.
 4. initially condensing asubstantial portion of said water vapor from said gaseous mixture toproduce a discrete readily removable fresh water condensate, 5.continuously removing portions of said discrete fresh water condensatefrom the locus of condensation thereof to provide a discrete immediatelyutilizable product,
 5. The method as set forth in claim 2 wherein saidproduct has a value of about 0.12.
 5. continuously removing portions ofsaid discrete fresh water condensate from the locus of condensationthereof to provide a discrete immediately utilizable product, 6.continuously encapsulating, essentially within a multi-elementbubble-like foam constituted by a multiplicity of interengaged films ofencapsulating liquid bodies of non-condensible components and residualwater vapor of said gaseous mixture in the upper portions of amultiplicity of elongate substantially vertical chambers in such mannerthat said foam encapsulated bodies, during the early portion of theirsubsequent downward displacement, are at least compositely substantiallyequal in area and dimension to the horizontal cross-section of saidchambers, said chambers having a horizontal cross-sectional area of suchcharacter that the product of the length in inches of the wettedperimeter thereof and the maximum distance in inches between any twopoints thereon has a numerical value of less than 0.6,
 6. continuouslyencapsulating, essentially within a multi-element bubble-like foamconstituted by a multiplicity of interengaged films of encapsulatingliquid, bodies of the non-condensible components and the residual watervapor of said gaseous mixture in the upper portion of at least oneelongate substantially vertical chamber in such manner that such foamencapsulated bodies during the early portion of their subsequentdownward displacement are at least compositely substantially equal inarea and dimension to the horizontal cross-section of said chamber, 7.selectively imparting downward displaceMent and concurrent compressionof said encapsulated bodies within the upper portion of said chamber bythe weight of the liquid defining subsequently encapsulated bodiesdisposed thereabove to provide an effluent deliverable from the lowerportion thereof,
 7. selectively imparting downward displacement andconcurrent compression of said encapsulated bodies within the upperportions of said chambers by the weight of the liquid definingsubsequently encapsulated bodies disposed thereabove to provide aneffluent deliverable from the lower portions thereof,
 8. releasing theeffluent from said multiplicity of chambers into a confined commonstream having a flow velocity that is relatively high compared to therate of flow of liquid through said chambers and is of a magnitude toeffect displacement of said effluent and any gas bodies containedtherein away from said chambers and transfer thereof to a locationexternal of the locus of evaporation,
 8. and maintaining the temperatureof the encapsulating liquid below the condensation point of the watervapor contained within said encapsulated bodies to effect substantialcondensation thereof during the downward displacement of said bodies. 9.and maintaining the temperature of the encapsulating liquid below thecondensation point of the water vapor contained within said encapsulatedbodies to effect substantial condensation thereof during the downwarddisplacement of said bodies.